Capacitor and method of production thereof

ABSTRACT

A capacitor includes a first electrode, a second electrode, and a dielectric layer of molecular material disposed between said first and second electrodes. The molecular material is described by the general formula: 
       D p -(Core)- H q , 
     where Core is a polarizable conductive anisometric core, having conjugated π-systems, and characterized by a longitudinal axis, D and H are insulating substituents, and p and q are numbers of the D and H substituents accordingly. And Core possesses at least one dopant group that enhances polarizability.

CLAIM OF PRIORITY

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 14/710,491, filed May 12, 2016, the entire contentsof which are incorporated herein by reference. U.S. patent applicationSer. No. 14/710,491 claims the priority benefit of U.S. ProvisionalPatent Application No. 61/991,871 filed May 12, 2015, the entirecontents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to passive components ofelectrical circuit and more particularly to a capacitor intended forenergy storage and method of production thereof.

BACKGROUND OF THE INVENTION

A capacitor is a passive electronic component that is used to storeenergy in the form of an electrostatic field, and comprises a pair ofelectrodes separated by a dielectric layer. When a potential differenceexists between two electrodes, an electric field is present in thedielectric layer. This field stores energy, and an ideal capacitor ischaracterized by a single constant value of capacitance which is a ratioof the electric charge on each electrode to the potential differencebetween them. In practice, the dielectric layer between electrodespasses a small amount of leakage current. Electrodes and leads introducean equivalent series resistance, and dielectric layer has limitation toan electric field strength which results in a breakdown voltage. Thesimplest energy storage device consists of two parallel electrodesseparated by a dielectric layer of permittivity ε, each of theelectrodes has an area S and is placed on a distance d from each other.Electrodes are considered to extend uniformly over an area S, and asurface charge density can be expressed by the equation: ±ρ=±Q/S. As thewidth of the electrodes is much greater than the separation (distance)d, an electrical field near the center of the capacitor will be uniformwith the magnitude E=ρ/ε. Voltage is defined as a line integral of theelectric field between electrodes. An ideal capacitor is characterizedby a constant capacitance C defined by the formula:

C=Q/V,   (1)

which shows that capacitance increases with area and decreases withdistance. Therefore the capacitance is largest in devices made ofmaterials of high permittivity.

A characteristic electric field known as the breakdown strength E_(bd),is an electric field in which the dielectric layer in a capacitorbecomes conductive. Voltage at which this occurs is called the breakdownvoltage of the device, and is given by the product of dielectricstrength and separation between the electrodes:

V _(bd)=E_(bd)d   (2)

The maximal volumetric energy density stored in the capacitor is limitedby the value proportional to ˜ε·E² _(bd), where ε is dielectricpermittivity and E_(bd) is breakdown strength. Thus, in order toincrease the stored energy of the capacitor it is necessary to increasedielectric permeability c and breakdown strength E_(bd) of thedielectric.

For high voltage applications much larger capacitors have to be used.There are a number of factors that can dramatically reduce the breakdownvoltage. Geometry of the conductive electrodes is important for theseapplications. In particular, sharp edges or points hugely increase theelectric field strength locally and can lead to a local breakdown. Oncea local breakdown starts at any point, the breakdown will quickly“trace” through the dielectric layer till it reaches the oppositeelectrode and causes a short circuit.

Breakdown of the dielectric layer usually occurs as follows. Theintensity of the electric field becomes high enough to free electronsfrom atoms of the dielectric material and the dielectric material beginsto conduct an electric current from one electrode to another. Presenceof impurities in the dielectric or imperfections of the crystalstructure can result in an avalanche breakdown as observed insemiconductor devices, such as avalanche diodes and avalanchetransistors.

Another important characteristic of a dielectric material is itsdielectric permittivity. Different types of dielectric materials areused for capacitors and include ceramics, polymer film, paper, andelectrolytic capacitors of different kinds. The most widely used polymerfilm materials are polypropylene and polyester. An important aspect ofdielectric permittivity is that an increase of dielectric permittivityincreases the maximum volumetric energy density that can be stored in acapacitor.

A material with an ultra-high dielectric constant was found to be thecomposite polyaniline, PANI-DBSA/PAA. PANI-DBSA/PAA is synthesized usingin situ polymerization of aniline in an aqueous dispersion ofpoly-acrylic acid (PAA) in the presence of dodecylbenzene sulfonate(DBSA) (Chao-Hsien Hoa et al., “High dielectric constantpolyaniline/poly(acrylic acid) composites prepared by in situpolymerization”, Synthetic Metals 158 (2008), pp. 630-637). Thewater-soluble PAA serves as a polymeric stabilizer, protecting the PANIparticles from macroscopic aggregation. A very high dielectric constantof ca. 2.0*10⁵ (at 1 kHz) is obtained for the composite containing 30%PANI by weight. SEM micrograph reveals that composites with high PANIcontent (i.e., 20 wt. %) consisted of numerous nano-scale PANI particlesthat are evenly distributed within the PAA matrix. The individualnano-scale PANI particles may be thought of as small capacitors. (Hoa etal.) attribute high dielectric constants to the sum of the smallcapacitors corresponding to the PANI particles. A major drawback of thismaterial is a possible occurrence of percolation and formation of atleast one continuous conductive path under electric field withprobability of such an event increasing with an increase of the electricfield. When at least one continuous path (track) through the neighboringconducting PANI particles is formed between electrodes of the capacitor,it decreases a breakdown voltage of the capacitor.

Single crystals of doped aniline oligomers are produced via a simplesolution-based self-assembly method (see, Yue Wang, et. al.,“Morphological and Dimensional Control via Hierarchical Assembly ofDoped Oligoaniline Single Crystals”, J. Am. Chem. Soc. 2012, 134, pp.9251-9262). Detailed mechanistic studies have revealed that crystals ofdifferent morphologies and dimensions can be produced by a “bottom-up”hierarchical assembly where structures such as one-dimensional (1-D)nanofibers can be aggregated into higher order architectures. A largevariety of crystalline nanostructures, including 1-D nanofibers andnanowires, 2-D nanoribbons and nanosheets, 3-D nanoplates, stackedsheets, nanoflowers, porous networks, hollow spheres, and twisted coils,can be obtained by controlling the nucleation of the crystals and thenon-covalent interactions between the doped oligomers. These nanoscalecrystals exhibit enhanced conductivity compared to their bulkcounterparts as well as interesting structure-property relationshipssuch as shape-dependent crystallinity. Furthermore, the morphology anddimension of these structures can be largely rationalized and predictedby monitoring molecule-solvent interactions via absorption studies.

There is a known energy storage device based on a multilayer structure.The energy storage device includes first and second electrodes, and amultilayer structure comprising blocking and dielectric layers. Thefirst blocking layer is disposed between the first electrode and adielectric layer, and the second blocking layer is disposed between thesecond electrode and a dielectric layer. Dielectric constants of thefirst and second blocking layers are both independently greater than thedielectric constant of the dielectric layer. FIG. 1 shows one exemplarydesign that includes electrodes 1 and 2, and multilayer structurecomprising layers made of dielectric material (3, 4, 5) which areseparated by layers of blocking material (6, 7, 8, 9). The blockinglayers 6 and 9 are disposed in the neighborhood of the electrodes 1 and2 accordingly and characterized by higher dielectric constant thandielectric constant of the dielectric material. A drawback of thisdevice is that blocking layers of high dielectric permittivity locateddirectly in contact with electrodes can lead to destruction of theenergy storage device. Materials with high dielectric permittivity whichare based on composite materials and contain polarized particles (suchas PANI particles) might demonstrate a percolation phenomenon. Theformed polycrystalline structure of layers has multiple tanglingchemical bonds on borders between crystallites. When a material with ahigh dielectric permittivity possesses a polycrystalline structure isused a percolation might occur along the borders of crystal grains.Another drawback of current devices is that they require the expensivemanufacturing procedure of vacuum deposition of all layers.

Capacitors as energy storage devices have well-known advantages versuselectrochemical energy storage, e.g. a battery. Compared to batteries,capacitors can store energy with very high power density, i.e.charge/recharge rates, have long shelf life with little degradation, andcan be charged and discharged (cycled) hundreds of thousands or millionsof times. However, capacitors often do not store energy in a smallvolume or weight as in a case of batteries, or at low energy storagecost, which makes capacitors impractical for some applications, forexample electric vehicles. Accordingly, it would be an advance in energystorage technology to provide capacitors of higher volumetric and massenergy storage density and lower cost.

The present invention solves a problem of the further increase ofvolumetric and mass density of reserved energy of the capacitor, and atthe same time reduces cost of materials and manufacturing process.

SUMMARY OF THE INVENTION

Embodiments of the present invention provides a capacitor comprising afirst electrode, a second electrode, and a dielectric layer of molecularmaterial disposed between said first and second electrodes. Saidelectrodes are flat and planar and positioned parallel to each other.The molecular material is described by the general formula:

D_(p)-(Core)-H_(q),   (I)

where Core is a polarizable conductive anisometric core, havingconjugated π-systems, and characterized by a longitudinal axis, D and Hare insulating substituents, and p and q are numbers of the D and Hsubstituents accordingly. The insulating substituents are selectivelyattached to any available positions on the polarizable anisometric coreincluding on apex positions and lateral positions as related thelongitudinal axis of the Core, and p and q are independently selectedfrom values 1, 2, 3, 4, and 5. And Core possesses one or more dopantgroups that enhance polarizability.

A method of producing a capacitor, which comprises the steps of a)preparation of a conducting substrate serving as one of the electrodes,b) application of a molecular material on the substrate, c) formation ofthe solid layer molecular material layer on the substrate, and d)formation of the second electrode on the solid molecular material layer,wherein the molecular material is described by the general formula:

D_(p)-(Core)-H_(q)   (I)

where Core is a conductive and polarizable anisometric core, havingconjugated π-systems, and characterized by a longitudinal axis, D and Hare insulating substituents, and p and q are numbers of the D and Hsubstituents accordingly. The insulating substituents are selectivelyattached to any available positions on the polarizable anisometric coreincluding apex positions and lateral positions as related thelongitudinal axis of the Core, and p and q are independently selectedfrom values 1, 2, 3, 4, and 5. And Core possesses one or more dopantgroups that enhance polarizability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration that shows a typical design of anenergy storage device according to the Prior Art.

FIG. 2 is a schematic illustration that shows a single molecule of amolecular material, according to an embodiment of the invention.

FIG. 3 is a schematic illustration that shows a disclosed capacitor witha hexagonal crystal structure in the dielectric layer of the molecularmaterial, according to an embodiment of the invention. The insert is aschematic illustration that shows a formation of twisted conductivestacks.

FIG. 4 is a schematic illustration that shows a dielectric layer of themolecular material, wherein the conductive stacks are formed with atwist angle equal to zero, according to an embodiment of the invention.

FIG. 5 is a schematic illustration that shows a disclosed capacitor witha lamellar structure of the dielectric layer of the molecular material,according to an embodiment of the invention.

FIG. 6 shows a cross-section of a multilayered tapes structure ofmetalized substrate electrode, an energy storage material, and a secondelectrode.

FIG. 7 shows an example of winding of a multilayered tape capacitor.

FIG. 8 shows an alternative embodiment of a wound capacitor.

FIG. 9 shows an example of a capacitive energy storage module having twoor more networked energy storage cells according to an alternativeaspect of the present disclosure.

FIG. 10 shows an example of a capacitive energy storage system havingtwo or more energy storage networked modules according to an alternativeaspect of the present disclosure.

FIG. 11 schematically shows an energy storage cell.

FIG. 12 shows a capacitive energy storage device containing a singlecapacitive element connected to a two terminal port.

DETAILED DESCRIPTION OF THE INVENTION

The general description of the present invention having been made, afurther understanding can be obtained by reference to the specificpreferred embodiments, which are given herein only for the purpose ofillustration and are not intended to limit the scope of the appendedclaims.

The present invention provides a capacitor as disclosed hereinabove. Thedisclosed capacitor comprises a first electrode, a second electrode, anda dielectric layer of molecular material disposed between said first andsecond electrodes. Said electrodes are flat and planar and positionedparallel to each other. A molecule of the molecular material(schematically shown in FIG. 2) described by general formula:

D_(p)-(Core)-H_(q),   (I)

where Core 10 is a polarizable conductive anisometric core, havingconjugated π-systems, and characterized by a longitudinal axis, andinsulating substituents D and H 11, and p and q are numbers ofsubstituents D and H accordingly. The insulating substituents areselectively attached to the polarizable anisometric core including onapex positions and lateral positions as related the longitudinal axis ofthe Core, and p and q are independently selected from values 1, 2, 3, 4,and 5. And Core possesses one or more dopant groups that enhancepolarizability.

The conductive anisometric core may be made further polarizable byadding a variety of dopant groups to various positions of the structure.Incorporating electron donors and electron acceptors is one way toenhance the polarizability. The electrophilic groups (acceptors) areselected from −NO₂, −NH₃ ⁺ and —NR₃ ⁺ (quaternary nitrogen salts),counterion Cl⁻ or Br⁻, —CHO (aldehyde), —CRO (keto group), —SO₃H(sulfonic acids), —SO₃R (sulfonates), SO₂NH₂ (sulfonamides), —COOH(carboxylic acid), —COOR (esters, from carboxylic acid side), —COCl(carboxylic acid chlorides), —CONH₂ (amides, from carboxylic acid side),—CF₃, CN, wherein R is radical selected from the list comprising alkyl(methyl, ethyl, isopropyl, tert-butyl, neopentyl, cyclohexyl etc.),allyl (—CH₂—CH═CH₂), benzyl (—CH₂C₆H₅) groups, phenyl (+substitutedphenyl) and other aryl (aromatic) groups. The nucleophilic groups(donors) are selected from —O⁻ (phenoxides, like —ONa or —OK), —NH₂,—NHR, —NR₂, —OH, —OR (ethers), —NHCOR (amides, from amine side), —OCOR(esters, from alcohol side), alkyls, —C₆H₅, vinyls, wherein R is radicalselected from the list comprising alkyl (methyl, ethyl, isopropyl,tent-butyl, neopentyl, cyclohexyl etc.), allyl (—CH2-CH═CH2), benzyl(—CH2C6H5) groups, phenyl (+substituted phenyl) and other aryl(aromatic) groups. The existence of electrophilic groups (acceptors) andnucleophilic groups (donors) in the aromatic polycyclic conjugatedmolecule promotes the electronic polarizability of these molecules.Under the influence of an external electric field, electrons aredisplaced from the nucleophilic groups (donors) to the electrophilicgroups (acceptors) this leads to increases in the electronicpolarizability of such molecules. Thus the distribution of electronicdensity in these molecules is non-uniform. The presence ofelectro-conductive oligomers leads to a further increase of thepolarization ability of the disclosed electro-polarizable compoundbecause of electronic super conductivity of the electro-conductiveoligomers. Ionic groups increase an ionic component of polarization ofthe disclosed electro-polarizable compound. Non-limiting examples ofmodified cores include rylene and fused rylene fragments where dopantsmay be placed on any ring in the system. The insulating tails may beattached to the ring structure or may be attached to the dopant groups.Herein we define the term “rylene fragment” to include any polyaromaticsystem with the rylene motif and may or may not be fused with other ringsystems.

TABLE 1 Examples of the polycyclic organic compound comprising therylene motif, where n is an integer greater than or equal to 0 andpreferentially ranges between 0 and 8.

1

2

3

4

5

6

7

8

9

10

11

12

13

A method of producing a capacitor, which comprises the steps of a)preparation of a conducting substrate serving as one of the electrodes,b) application of a molecular material on the substrate, c) formation ofthe solid layer molecular material layer on the substrate, and d)formation of the second electrode on the solid molecular material layer,wherein the molecular material is described by the general formula:

D_(p)-(Core)-H_(q)   (I)

where Core is a conductive and polarizable anisometric core, havingconjugated π-systems, and characterized by a longitudinal axis, D and Hare insulating substituents, and p and q are numbers of the D and Hsubstituents accordingly. The insulating substituents are selectivelyattached to any available positions on the polarizable anisometric coreincluding at apex positions and lateral positions as related to thelongitudinal axis, and p and q are independently selected from values 1,2, 3, 4, and 5. And, Core possesses one or more dopant groups thatenhance polarizability. Wherein, the one or more dopant groups areselectively attached to the anisometric core to enhance both linear andnonlinear polarizability of the compound.

The anisometric core is a flat molecular system having thickness notexceeding 0.34±0.03 nm and unequal dimensions. It can be characterizedby a longitudinal axis which is an axis along the lengthwise directionof the core.

In one embodiment of the disclosed capacitor at least one of theinsulating groups D and at least one of the insulating groups H areindependently selected from the list comprising alkyl, fluorinatedalkyl, chlorinated alkyl, branched and complex alkyl, branched andcomplex fluorinated alkyl, branched and complex chlorinated alkylgroups, and any combination thereof.

In one embodiment of the disclosed capacitor the anisometric cores formconductive stacks due to π-π-interaction, and the insulatingsubstituents form the insulating sublayers surrounding said stacks. Thelongitudinal axes of the adjacent anisometric cores form a twist angleα, said twist angle is in the range of 0°≦α≦90°, and distance betweenthe cores in the stacks is 0.34±0.03 nm.

Depending on the application of the device, a dielectric permittivity ofthe insulating sublayer material formed with the insulating substitutesε_(ins) can be in the broad range; for most embodiments it is in therange between about 2 and 25. The insulating sublayer material ischaracterized by a band gap of greater than 4 eV. The insulatingsublayer is characterized by a breakdown field strength being in therange between about of 0.01 V/nm and 10 V/nm. Due to high polarizabilityof the anisometric cores, the conductive molecular stacks possessrelatively high dielectric permittivity ε_(cor) in comparison withdielectric permittivity of the insulating sublayer ε_(ins). Thus, theconductive polarizable stacks possess dielectric permittivity ε_(cor),which is ten to one hundred thousand times higher than dielectricpermittivity ε_(ins) of the insulating sublayer. Therefore, electricfield intensity in the insulating sublayer E_(ins) and electric fieldintensity in the conductive polarizable molecular stacks E_(cor)satisfy:

E _(cor)=(ε_(ins)/ε_(cor))·E _(ins).   (1)

Electric field intensity E_(cor) is much less than electric fieldintensity E_(ins) and the voltage enclosed to the energy storage deviceis distributed over the insulating sublayers. In order to increase aworking voltage of the energy storage device it is necessary to increasenumber of the insulating sublayers.

In one embodiment of the present invention the anisometric cores formtwisted conductive stacks, wherein the longitudinal axes (indicated bydashed lines in the insert in FIG. 3) of the adjacent anisometric coresare twisted with respect to each other at a twist angle α. In yetanother embodiment the dielectric layer has a hexagonal crystalstructure.

In the schematic view in FIG. 3 the capacitor comprises two electrodes13 and 14 and dielectric layer 15 which comprises the anisotropictwisted stacks 12 surrounded with insulating sublayers 16. The term“hexagonal structure” is referred to the molecular material structure ofthe dielectric layer comprising the twisted conductive stacks. Thedielectric layer is characterized by a dense packing of the twistedstacks located parallel to each other. The projections of these stacksonto a plane normal to them form the two-dimensional structurepossessing hexagonal symmetry.

In one embodiment of the disclosed capacitor the anisometric cores formconductive stacks with the twist angle equal to zero. The longitudinalaxes of the anisometric cores in one stack are parallel to each otherand perpendicular to the surface of said electrodes. FIG. 4schematically shows the stack 12 formed with the anisometric cores andthe insulating sublayers 16 formed with the insulating substituents. Theinsulating substituents form the insulating sublayers between theconductive stacks and also between the conductive stacks and electrodes.The additional role of the insulating substitutes is increasing of thework function in the molecular material. Work function is the minimumamount of energy required to remove an electron from the surface of theconductive stack.

In yet another embodiment the molecular material has a lamellar crystalstructure. Lamellar structures or microstructures are composed of thealternating fine layers (sublayers) of different materials and/orregions of different structure and/or properties, as for example in alamellar polyethylene. In the present invention the fine layers of theconductive stacks are alternating with the amorphous sublayers of theinsulating substituents. FIG. 5 shows a capacitor with the lamellarstructure of the dielectric layer, according to an embodiment of theinvention. The capacitor comprises two electrodes 13 and 14, thedielectric layer 15 which comprises the fine layers of the conductivestacks 12 formed with the polarizable anisometric cores, and isotropicinsulating sublayers 16.

The polarizable anisometric cores of the molecular material of thedisclosed capacitor may possess translation periodicity and symmetry inat least one direction. The properties of a system with translationalsymmetry do not change when the material shifts on a certain vectorwhich is called a translation vector. In some instances, crystals of thedisclosed molecular material may possess a translational symmetry in allthree directions.

In one embodiment of the present invention, the polarizable anisometriccore is electroconductive oligomer comprising monomers having conjugatedπ-systems and the electroconductive oligomers form molecular stacks dueto π-π-interaction and stacks are positioned parallel to surface of theplanar electrode. In one embodiment of the present invention, theelectroconductive oligomers are selected from the list comprisingfollowing structural formulas corresponding to one of structures 14 to33 as given in Tables 2A, 2B, and 2C.

TABLE 2A Examples of the electroconductive oligomers

14

15

16

17

18

19

20where n equals to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

TABLE 2B Examples of the electroconductive oligomers

21

22

23

24

25

26where n and m are independently an integer between 1 and 100, and phenylgroups conjugated by azo-bridges in the above examples can be extendedto 3, 4, 5, 6, 7, 8, 9, 10, etc.

TABLE 2C Examples of the electroconductive oligomers

27

28

29

30

31

32

33where n is an integer between 1 and 100.

In another implementation of the organic compound, the Core in the abovegeneral structural formula comprises an electro-conductive oligomer ofazo-dye chromophores. The repeating backbone may contain a portion ofthe chromophore or possess a handle allowing the chromophore to bepresent as sidechains. Sidechains may be added to the final backboneproduct or incorporated into individual monomers that are thenpolymerized. If incorporated into the backbone the chromophores may bemodified such that they react with the other segments of the backbone toform the final product or they may be incorporated into monomers thatare then polymerized.

These chromophores impart high polarizability due to delocalization ofelectrons. This polarizability may be enhanced by dopant groups. Thecomposite oligomer may further include resistive tails that will provideinsulation within the material. In some embodiments, the resistive tailsmay be rigid in order to limit the motion of the sidechains, potentiallystabilizing pi-pi stacking interactions between sidechains whilesimultaneously making the material more stable by eliminating voids. Insome embodiments, the resistive tails may be rigid in order to limitvoids within the material. Non-limiting examples of repeating backbonesinclude, but is not limited to, (meth)acrylates, polyvinyls, peptides,peptoids, and polyimides.

Examples of suitable chromophores are, but are not limited to, DisperseRed-1, Black Hole Quencher-1, and Black Hole Quencher-2. In many of theembodiments it may not be necessary for all monomer units to bear achromophore, and in some it may be desirable to possess other sidechains or sites within the repeating backbone that impart otherqualities to the material such as stability, ease of purification,flexibility of finished film, etc.

For embodiments where the chromophores are incorporated as side chains,the resistive tails may be added before the sidechains are attached to afinished oligomer, after sidechains have been chemically added to afinished oligomer, or incorporated into the oligomer during synthesis byincorporation into monomer units.

For embodiments where the chromophore is part of the backbone the tailsmay be attached to the finished composite oligomer or incorporated intomonomer units and added during composite synthesis.

Non-limiting examples of suitable tails are alkyl, haloalkyl, cycloakyl,cyclohaloalkyl, and polyether. Such compounds and their synthesis aredescribed in U.S. patent application Ser. No. 15/090,509 (AttorneyDocket No. CSI-051) and U.S. patent application Ser. No. 15/163,595(Attorney Docket No. CSI-51B) which are herein incorporated by referencein their entirety.

Electrodes of the disclosed capacitor may be made of any suitablematerial, including but not limited to metals such as Pt, Cu, Al, Ag orAu; metal alloys, graphene, graphite, or ribtan. The electrodes may besubstantially planar (substantially not rough) and in parallel. Furtherstill, the electrodes optionally consist of multiple molecular layers onsubstrates of said metal or graphite. The molecular layers beingdescribed in U.S. patent application Ser. No. 15/368,171 (Attorneydocket number CSI-078) filed Dec. 2, 2016 and fully incorporated byreference herein.

Alternatively, the first electrode may be of a metalized tape consistingof a substrate film and one metalized face-side. Wherein the metalizedface-side consisting of any metal or combination thereof. The substratefilm may consist of polycarbonate, polyethylene terephthalate (PET, alsoknown as polyester), polypropylene, polystyrene, and polysulfone. In analternative embodiment, said substrate film may consist of the energystorage material described hereinabove.

In some embodiments, the capacitor can be coiled as in FIG. 7. Furtherschema and methods of production are taught in U.S. patent applicationSer. No. 14/752,600 filed on Jun. 26, 2015 (Attorney Docket No. CSI-017)which is fully incorporated by reference herein.

In some embodiments, the capacitor can be produced by a variety ofmanufacturing methods, which in general comprise the steps of a)preparation of a conducting substrate serving as one of the electrodes,b) application of a molecular material on the substrate, c) formation ofthe solid layer molecular material layer on the substrate, and d)formation of the second electrode on the solid molecular material layer,wherein the molecular material is described by the general formula:

D_(p)-(Core)-H_(q)   (I)

where Core 10 is a polarizable conductive anisometric core, havingconjugated π-systems and characterized by a longitudinal axis, D and Hare insulating substituents, and p and q are numbers of substituents Dand H accordingly. The insulating substituents are selectively attachedto the polarizable anisometric core including at apex positions andlateral positions as related to the longitudinal axis, and p and q areindependently selected from values 1, 2, 3, 4, and 5. And, Corepossesses one or more dopant groups that enhance polarizability.Wherein, the one or more dopant groups are selectively attached to theanisometric core to enhance both linear and nonlinear polarizability ofthe compound.

In one embodiment of the disclosed method at least one of the insulatinggroups D and at least one of the insulating groups H are independentlyselected from the list comprising alkyl, fluorinated alkyl, chlorinatedalkyl, branched and complex alkyl, branched and complex fluorinatedalkyl, branched and complex chlorinated alkyl groups, and anycombination thereof.

In one embodiment of the disclosed method the application step b)comprises application of a solution of the molecular material, and thesolid layer formation step c) comprises drying to form a solid molecularmaterial layer.

In yet another embodiment of the disclosed method the application stepb) comprises application of a melt of the molecular material, and thesolid layer formation step c) comprises cooling down to form a solidmolecular material layer.

In order that the embodiments of the invention may be more readilyunderstood, reference is made to the following example, which isintended to be illustrative of the invention, but is not intended to belimiting in scope.

In an aspect, the present disclosure provides a crystal dielectric layercomprising the disclosed organic compound. The crystal dielectric layersare produced from the disclosed organic compound by CascadeCrystallization. The arrangement of electrophilic groups (acceptors) andnucleophilic groups (donors) on the aromatic polycyclic conjugated corepromote formation of supramolecules.

The Cascade Crystallization process involves a chemical modificationstep and four steps of ordering during the crystal dielectric layerformation. The chemical modification step introduces hydrophilic groupson the periphery of the molecule of the disclosed organic compound inorder to impart amphiphilic properties to the molecule. Amphiphilicmolecules stack together into supramolecules, which is the first step ofordering. The supramolecules are then converted into aliquid-crystalline state to form a liquid crystal such a lyotropicliquid crystal or thermotropic liquid crystal, which is the second stepof ordering. The liquid crystal ordering can be manipulated via solventconcentration (which may be determined by the supramolecules' criticalmicelle concentration), temperature as related to the transition phasesof the liquid crystal, an applied external electric or magnetic field toorient dipoles of liquid crystal molecules, or any combination thereof.The lyotropic liquid crystal or thermotropic liquid crystal is then, forexample, deposited under the action of a shear force (or meniscus force)onto a substrate using the Mayer Rod shearing technique, so that shearforce (or the meniscus) direction determines the crystal axis directionin the resulting solid crystal layer. The external alignment upon theliquid crystal, can be produced using any other means, for example byapplying an external electric field at normal or elevated temperature,with or without additional illumination, electric field, magnetic field,or optical field (e.g., coherent photovoltaic effect); the degree of theexternal alignment should be sufficient to impart necessary orientationto the supramolecules of the lyotropic liquid crystal and form astructure, which serves as a base of the crystal lattice of the crystaldielectric layer. This directional deposition is third step of ordering,representing the global ordering of the crystalline or polycrystallinestructure on the substrate surface. The last step of the CascadeCrystallization process is drying/crystallization, which converts theliquid crystal into a solid crystal dielectric layer. The term CascadeCrystallization process is used to refer to the chemical modificationand four ordering steps as a combination process.

The Cascade Crystallization process is used for production of thincrystalline dielectric layers. The dielectric layer produced by theCascade Crystallization process has a global order which means that adirection of the crystallographic axis of the layer over the entiresubstrate surface is controlled by the deposition process. Molecules ofthe deposited material are packed into supramolecules with a limitedfreedom of diffusion or motion. The thin crystalline dielectric layer ischaracterized by an interplanar spacing of 0.34±0.03 nm—in the directionof one of the optical axes.

EXAMPLE 1

Example 1 describes a capacitor comprising a dielectric layer formedwith the solid molecular material of lamellar structure as shown in FIG.5.

The capacitor comprises two electrodes 13 and 14, the dielectric layer15 which comprises the conductive anisometric stacks 12 formed with thepolarizable anisometric cores, and isotropic insulating sublayers 16.Polyaniline (PANI) is used as the polarizable anisometric core, andfluorinated alkyl substituents are used as the insulating substituents.The conductive anisometric stacks formed with polyaniline (PANI) havethe dielectric permittivity ε_(cor) equal to 10,000. Thickness of eachinsulating sublayers formed by the substituents is approximatelyd_(ins)=2 nm, and number of the insulating sublayers n_(ins) is equal to500. Electrodes 13 and 14 are made of copper. Dielectric permittivity ofthe insulating sublayers is equal to 2.2 (i.e. ε_(ins)=2.2) and itsbreakdown voltage is equal to 1 V/nm. The working voltage of thecapacitor does not exceed the breakdown voltage Vbd which isapproximately equal to 1000 V.

In some embodiments, the capacitor may be incorporated into energystorage elements called energy storage devices, energy storage cells,energy storage modules, and energy storage systems. These energy storageelements are further described in U.S. patent application 15/043,315filed on Feb. 12, 2016.

As an aspect of the present disclosure, a capacitive energy storagemodule 40, e.g., as illustrated in FIG. 9. In the illustrated example,the energy storage module 40 includes two or more energy storage cells30 of the type described above. Each energy storage cell includes acapacitive energy storage device 34 having one or more capacitors 33 anda DC-voltage converter 31, which may be a buck converter, boostconverter, or buck/boost converter. In addition, each module may includea control board 32 of the type described below with respect to FIG. 11and an (optional) cooling mechanism (not shown). The module 40 mayfurther include an interconnection system that connects the anodes andcathodes of the individual energy storage cells to create a common anodeand common cathode of the capacitive energy storage module.

In yet another aspect, some implementations, the interconnection systemincludes a parameter bus 42 and power switches PSW. Each energy storagecell 30 in the module 40 may be coupled to the parameter bus 42 via thepower switches PSW. These switches allow two or more modules to beselectively coupled in parallel or in series via two or more rails thatcan serve as the common anode and common cathode. The power switches canalso allow one or more energy storage cells to be disconnected from themodule, e.g., to allow for redundancy and/or maintenance of cellswithout interrupting operation of the module. The power switches PSW maybe based on solid state power switching technology or may be implementedby electromechanical switches (e.g., relays) or some combination of thetwo.

In some implementations, the energy storage module further comprises apower meter 44 to monitor power input or output to the module. In someimplementations, the energy storage module further comprises a networkedcontrol node 46 configured to control power output from and power inputto the module. The networked control node 46 allows each module to talkwith a system control computer over a high speed network. The networkedcontrol node 46 includes voltage control logic circuitry 50 configuredto selectively control the operation of each of voltage controller 31 ineach of the energy storage cells 34, e.g., via their respective controlboards 32. The control node 46 may also include switch control logiccircuitry 52 configured to control operation of the power switches PSW.The control boards 32 and power switches PSW may be connected to thecontrol node 46 via a data bus 48. The voltage control and switchinglogic circuitry in the networked control node 46 may be implemented byone or more microprocessors, microcontrollers, application specificintegrated circuits (ASICs), field programmable gate arrays (FPGAs), orcomplex programmable logic devices (CPLDs). The control node 46 mayinclude a network interface 54 to facilitate transfer of signals betweenthe voltage control logic circuitry 50 and the control boards 32 on theindividual energy storage cells 34 and also to transfer signals betweenthe switching logic circuitry 52 and the power switches PSW, e.g., viathe data bus 48.

According to yet another aspect of the present disclosure a capacitiveenergy storage system may include two or more networked capacitiveenergy storage modules, e.g., of the type shown in FIG. 9. Oneembodiment of such a capacitive energy storage system 60 is shown inFIG. 10. The system 60 includes two or more energy storage modules 40 ofthe type shown in FIG. 9. Each capacitive energy storage module 40includes two or more capacitive energy storage cells 30, e.g., of thetype shown in FIG. 11 connected by an interconnection system 42 andcontrolled by a control node 46. Each capacitive energy storage modulemay also include a module power meter 44. Although it is not shown inFIG. 9, each control node 46 may include voltage control logic circuitry50 to control voltage controllers within the individual capacitiveenergy storage cells 30 and switching logic circuitry 52 to controlinternal power switches with the module, as described above. Inaddition, each control node 46 includes an internal data bus 48 and anetwork interface 54, which may be connected as described above. Powerto and from capacitive energy storage modules 40 is coupled to a systempower bus 62 via system power switches SPSW, which may be based on solidstate power switching technology or may be implemented byelectromechanical switches (e.g., relays) or some combination of thetwo. In some implementations, there may be an inverter (not shown)coupled between each capacitive energy storage module 40 and the systempower bus 62 to convert DC power from the module to AC power or viceversa.

The system 60 includes a system controller 66 connected to a system databus 68. The system controller may include switching control logic 72,voltage control logic 70, and system network interface 74. The voltagecontrol logic 70 may be configured to control the operation ofindividual DC-voltage controllers within individual cells 30 ofindividual modules 40. The switching control logic 72 may be configuredto control operation of the system power switches SPSW and also thepower switches PSW within individual capacitive energy storage modules40. Voltage control signals may be sent from the voltage control logic72 to a specific DC-voltage control device 31 within a specificcapacitive energy storage cell 30 of a specific capacitive energystorage module through the network interface 74, the system data bus 68,the module network interface 54 of the control node 46 for the specificmodule, the module data bus 48, and the control board 4 of theindividual cell 1.

By way of example, and not by way of limitation, the system controller66 may be a deterministic controller, an asynchronous controller, or acontroller having distributed clock. In one particular embodiment of thecapacitive energy storage system 60, the system controller 66 mayinclude a distributed clock configured to synchronize severalindependent voltage conversion devices in one or more capacitive energystorage cells of one or more of the capacitive energy storage modules40.

Aspects of the present disclosure allow for electrical energy storage ona much larger scale than possible with conventional electrical energystorage systems. A wide range of energy storage needs can be met byselectively combining one or more capacitors with a DC-voltageconversion devices into a cell, combining two or more cells into amodule, or combining two or more modules into systems.

As depicted in FIG. 11, in one embodiment of the energy storage cell 30,each of the one or more capacitors 33 comprises a first electrode 23, asecond electrode 25, and a dielectric material layer of the typedescribed in the current disclosure 24 disposed between said first andsecond electrodes. The electrodes 23, 25 may be made of a metal, such ascopper, zinc, or aluminum or other conductive material and are generallyplanar in shape. In one implementation, the electrodes and dielectricmaterial layer 24 are in the form of long strips of material that aresandwiched together and wound into a coil along with an insulatingmaterial, e.g., a plastic film such as polypropylene or polyester toprevent electrical shorting between the electrodes 23, 25. Although asingle capacitor 33 is shown for convenience in FIG. 11, aspects of thepresent disclosure are not limited to such implementations. Thoseskilled in the art will recognize that the capacitive energy storagedevice 34 may include multiple capacitors 33 connected in parallel toprovide a desired amount of energy storage capacity that scales roughlywith the number of capacitors in parallel. Alternatively, the capacitiveenergy storage device 34 may include two or more capacitors connected inseries to accommodate a desired voltage level. In addition, thecapacitive energy storage device 34 may include combinations of three ormore capacitors in a capacitor network involving various series andparallel combination.

In yet another implementation, the capacitive energy storage devices maycomprise more than one of the capacitors connected in series orparallel. In still another implementation, the capacitive energy storagedevice may further comprise a cooling mechanism 36. In someimplementations, the cooling can be passive, e.g., using radiativecooling fins on the capacitive energy storage device 34 and DC-voltageconversion device 31. Alternatively, a fluid such as air, water orethylene glycol can be used as a coolant in an active cooling system. Byway of example, and not by way of limitation, the cooling system 36 mayinclude conduits in thermal contact with the capacitive energy storagedevice 34 and DC-voltage conversion device 31. The conduits are filledwith a heat exchange medium, which may be a solid, liquid or gas. Insome implementations, the cooling mechanism may include a heat exchangerconfigured to extract heat from the heat exchange medium. In otherimplementations, the cooling mechanism 36 may include conduits in theform of cooling fins on the capacitive energy storage device 34 andDC-voltage conversion device 31 and the heat exchange medium is air thatis blown over the cooling fins, e.g., by a fan. In another embodiment ofthe present invention, the heat exchanger 37 may include a phase-changeheat pipe configured to carry out cooling. The cooling carried out bythe phase-change heat pipe may involve a solid to liquid phase change(e.g., using melting of ice or other solid) or liquid to gas phasechange (e.g., by evaporation of water or alcohol) of a phase changematerial. In yet another implementation, the conduits or heat exchanger37 may include a reservoir containing a solid to liquid phase changematerial, such as paraffin wax.

Referring again to FIG. 11 the DC-voltage conversion device 31 mayinclude a buck converter for applications in which V_(out)<V_(in), aboost converter for applications in which V_(out)>V_(in), or abidirectional buck/boost converter for applications in whichV_(out)<V_(in) in certain situations and V_(out)>V_(in) in othersituations.

FIG. 12 depicts a capacitive energy storage device with a singlecapacitor 33. Without limitation such devices may have multiplecapacitors coupled in series to accommodate a higher voltage level or inparallel to increase the overall capacitance of the system.

Although the present invention has been described in detail withreference to a particular preferred embodiment, persons possessingordinary skill in the art to which this invention pertains willappreciate that various modifications and enhancements may be madewithout departing from the spirit and scope of the claims that follow.

What is claimed is:
 1. A capacitor comprising: a first electrode, asecond electrode, and a dielectric layer of molecular material disposedbetween said first and second electrodes, wherein said electrodes aresubstantially planar surface and positioned parallel to each other, andthe molecular material is described by the general formulaD_(p)-(Core)-H_(q)   (I) where Core is a polarizable conductiveanisometric core, having conjugated π-systems, and characterized by alongitudinal axis, D and H are insulating substituents, and p and q arenumbers of the D and H substituents accordingly, wherein saidsubstituents are selectively attached to any available positions on thepolarizable anisometric core including apex positions and lateralpositions as related to the longitudinal axis, p and q are independentlyselected from values 1, 2, 3, 4, and 5, and Core possesses one or moreselectively attached dopant groups that enhance polarizability.
 2. Acapacitor, according to claim 1, wherein the conductive anisometric coreconjugated π-systems form supramolecular structures by means ofπ-π-interactions.
 3. A capacitor, according to claim 1, wherein theinsulating substituents D and H are selected independently from thegroup consisting of alkyl, fluorinated alkyl, chlorinated alkyl,branched and complex alkyl, branched and complex fluorinated alkyl,branched and complex chlorinated alkyl groups, and any combinationthereof.
 4. A capacitor, according to claim 1, wherein one or more ofthe insulating groups D and one or more of the insulating groups H areeach selected independently from the group consisting of alkyl,fluorinated alkyl, chlorinated alkyl, branched and complex alkyl,branched and complex fluorinated alkyl, branched and complex chlorinatedalkyl groups, and any combination thereof.
 5. A capacitor, according toclaim 1, wherein the one or more dopant groups are selected from thegroup consisting of —NO₂, —NH₃ ⁺and —NR₃ ⁺ (quaternary nitrogen salts),counterion Cl⁻, counterion Br⁻, —CHO (aldehyde), —CRO (keto group),—SO₃H (sulfonic acids), —SO₃R (sulfonates), SO₂NH₂ (sulfonamides), —COOH(carboxylic acid), —COOR (esters, from carboxylic acid side), —COCl(carboxylic acid chlorides), —CONH₂ (amides, from carboxylic acid side),—CF₃, —CCl₃, —CN, wherein R is radical selected from the list comprisingalkyl (methyl, ethyl, isopropyl, tert-butyl, neopentyl, cyclohexyletc.), allyl (—CH₂—CH═CH₂), benzyl (—CH₂C₆H₅) groups, phenyl(+substituted phenyl) and other aryl (aromatic) groups. The nucleophilicgroups (donors) are selected from —O⁻ (phenoxides, like —ONa or —OK),—NH₂, —NHR, —NR₂, —OH, —OR (ethers), —NHCOR (amides, from amine side),—OCOR (esters, from alcohol side), alkyls, —C₆H₅, vinyls, wherein R isradical selected from the list comprising alkyl (methyl, ethyl,isopropyl, tent-butyl, neopentyl, cyclohexyl etc.), allyl (—CH2-CH═CH2),benzyl (-CH2C6H5) groups, phenyl (+substituted phenyl) and other aryl(aromatic) groups.
 6. A capacitor according to claim 1, wherein Coreincludes one or more rylene fragments.
 7. A capacitor according to claim1, wherein Core includes one or more rylene fragments selected from thelist:

where n=0, 1, 2, 3, 4, 5, 6, 7, 8; wherein the one or more dopant groupsmay be on any ring; and wherein when there are more than one dopantgroups, the dopant groups are positioned on an equal or fewer number ofrings than there are dopant groups.
 8. A capacitor according to claim 1,wherein one or more of said insulating groups is connected to the Corevia one or more of said one or more dopant groups.
 9. A capacitoraccording to claim 6, wherein one or more of said insulating groups isconnected to the Core via one or more of said dopant groups.
 10. Acapacitor according to claim 1, wherein said Core is comprised of aconjugated system wherein aromatic rings are connected via alternatingsingle and double chain bonds and a repeating backbone, wherein any, andup to all, of the conjugated chemical structure may simultaneously bethe repeating backbone.
 11. A capacitor according to claim 1, whereinsaid Core is selected from the group consisting of the followingstructural formulas 1 to 13:

where n equals to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, and

where n and m are independently an integer between 1 and 100, and phenylgroups conjugated by azo-bridges in the above examples can be extendedto 3, 4, 5, 6, 7, 8, 9,
 10. 12. A capacitor according to claim 1,wherein the first and second electrodes are made of a metal.
 13. Acapacitor according to claim 1, wherein the first and second electrodesare made of any metal and further comprises one or more molecular layersselected from an electro-conductive layer, a field-planarization layer,a tunneling injection blocking layer, a coulomb blocking layer or anycombination thereof.
 14. A capacitor according to claim 1, wherein oneor both of the first and second electrodes are made of copper, said Coreincludes polyaniline (PANI), and the insulating substituents D and Hinclude fluorinated alkyl substituents.
 15. A capacitor according toclaim 1, wherein said first electrode includes a metalized tape having aplastic substrate and a metal layer.
 16. A capacitor according to claim15, wherein said plastic substrate has a thickness between about 3 μmand about 12 μm.
 17. A capacitor according to claim 16, wherein saidplastic substrate includes a molecular material described by the generalformulaD_(p)-(Core)-H_(q)   (I) where Core is a polarizable conductiveanisometric core, having conjugated π-systems, and characterized by alongitudinal axis, which form supramolecular structures by means ofπ-π-interaction, D and H are insulating substituents, and p and q arenumbers of the D and H substituents accordingly, wherein saidsubstituents are selectively attached to any available positions on thepolarizable anisometric core including apex positions and lateralpositions as related to the longitudinal axis, p and q are independentlyselected from values 1, 2, 3, 4, and 5, Core possesses two or moredopant groups that enhances polarizability; wherein one or more of theinsulating groups D and one or more of the insulating groups H is eachselected independently from the group consisting of alkyl, fluorinatedalkyl, chlorinated alkyl, branched and complex alkyl, branched andcomplex fluorinated alkyl, branched and complex chlorinated alkylgroups, and any combination thereof; and wherein the at two or moredopant groups are independently selected from: —NO₂, —NH₃ ⁺ and —NR₃ ⁺(quaternary nitrogen salts), counterion Cl⁻, counterion Br⁻, —CHO(aldehyde), —CRO (keto group), —SO₃H (sulfonic acids), —SO₃R(sulfonates), SO₂NH₂ (sulfonamides), —COOH (carboxylic acid), —COOR(esters, from carboxylic acid side), —COCl (carboxylic acid chlorides),—CONH₂ (amides, from carboxylic acid side), —CF₃, —CCl₃, —CN, wherein Ris radical selected from the list comprising alkyl (methyl, ethyl,isopropyl, tert-butyl, neopentyl, cyclohexyl etc.), allyl (—CH₂—CH═CH₂),benzyl (—CH₂C₆H₅) groups, phenyl (+substituted phenyl) and other aryl(aromatic) groups. The nucleophilic groups (donors) are selected from—O⁻ (phenoxides, like —ONa or —OK), —NH₂, —NHR, —NR₂, —OH, —OR (ethers),—NHCOR (amides, from amine side), —OCOR (esters, from alcohol side),alkyls, —C₆H₅, vinyls, wherein R is radical selected from the listcomprising alkyl (methyl, ethyl, isopropyl, tent-butyl, neopentyl,cyclohexyl etc.), allyl (—CH2-CH═CH2), benzyl (—CH2C6H5) groups, phenyl(+substituted phenyl) and other aryl (aromatic) groups.
 18. An energystorage cell comprising: one or more capacitive energy storage devices;and a DC-voltage conversion device; wherein each of the one or morecapacitive energy storage devices includes one or more capacitors as inclaim 1, wherein the output voltage of the capacitive energy storagedevice is an input voltage of the DC-voltage conversion device duringdischarging the capacitive energy storage device,wherein the inputvoltage of the capacitive energy storage device is an output voltage ofthe DC-voltage conversion device while charging the capacitive energystorage device.
 19. A method of producing a capacitor, which comprisesthe steps of; a) preparation of a conducting substrate serving as one ofthe electrodes; b) application of a molecular material on the substrate;c) formation of the solid layer of the molecular material; and d)formation of the second electrode on the solid molecular material layer;wherein the molecular material is described by the general formulaD_(p)-(Core)-H_(q)   (I) where Core is a polarizable conductiveanisometric core, having conjugated π-systems and characterized by alongitudinal axis, D and H are insulating substituents, p and q arenumbers of the D and H substituents accordingly, wherein saidsubstituents are selectively attached to any available positions on thepolarizable anisometric core including on apex positions and lateralpositions as related to the longitudinal axis, and p and q areindependently selected from values 1, 2, 3, 4, and 5, and Core possessesone or more selectively attached dopant groups that enhancepolarizability.
 20. A method according to claim 19, wherein wherein theone or more dopant groups are selected from the group consisting of—NO₂, —NH₃ ⁺ and —NR₃ ⁺ (quaternary nitrogen salts), counterion Cl⁻,counterion Br⁻, —CHO (aldehyde), —CRO (keto group), —SO₃H (sulfonicacids), —SO₃R (sulfonates), SO₂NH₂ (sulfonamides), —COOH (carboxylicacid), —COOR (esters, from carboxylic acid side), —COCl (carboxylic acidchlorides), —CONH₂ (amides, from carboxylic acid side), —CF₃, —CCl₃,—CN, wherein R is radical selected from the list comprising alkyl(methyl, ethyl, isopropyl, tert-butyl, neopentyl, cyclohexyl etc.),allyl (—CH₂—CH═CH₂), benzyl (—CH₂C₆H₅) groups, phenyl (+substitutedphenyl) and other aryl (aromatic) groups. The nucleophilic groups(donors) are selected from —O⁻ (phenoxides, like —ONa or —OK), —NH₂,—NHR, —NR₂, —OH, —OR (ethers), —NHCOR (amides, from amine side), —OCOR(esters, from alcohol side), alkyls, —C₆H₅, vinyls, wherein R is radicalselected from the list comprising alkyl (methyl, ethyl, isopropyl,tent-butyl, neopentyl, cyclohexyl etc.), allyl (—CH2-CH═CH2), benzyl(—CH2C6H5) groups, phenyl (+substituted phenyl) and other aryl(aromatic) groups.
 21. A method according to claim 19, wherein theapplication step b) comprises application of a solution of the molecularmaterial, and the solid layer formation step c) comprises drying to forma solid molecular material layer.
 22. A method according to claim 19,wherein the application step b) comprises application of a melt of themolecular material, and the solid layer formation step c) comprisescooling down to form a solid molecular material layer.